Catalytic Oxidation and Reduction of Polycyclic Aromatic Hydrocarbons (PAHs) Present as Mixtures in Hydrothermal Media

Abstract

The reactivity of fluorene, anthracene and fluoranthene under oxidation and reduction conditions has been investigated in this study. This project looks at catalytic and green approaches of converting PAH to less toxic and/or less stable derivatives that are amenable to

Exploring Compositional Changes along In Situ Combustion and Their Implications on Emulsion Stabilization via Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS)

“…Oxidation tendency of aromatic hydrocarbons increases with aromaticity (number of aromatic rings). For instance, pyrene is more readily oxidized than anthracene, and this last is less stable than naphthalene under oxidative conditions . This fact might explain the trend observed in Figure , where the more-aromatic compounds reduced their concentrations along the process while the less-aromatic compounds increase their abundances.…”

“…For instance, pyrene is more readily oxidized than anthracene, and this last is less stable than naphthalene under oxidative conditions. 37 This fact might explain the trend observed in Figure 5, where the morearomatic compounds reduced their concentrations along the process while the less-aromatic compounds increase their abundances. Although cracking/upgrading reactions might also occur, 2,5 it is not possible to propose this conclusion, considering the slight variations in carbon number and molecular weight (see Figures S1 and S2 and Table S1 in the Supporting Information).…”

“…The raw oil (Scenario Sc1) had the lowest concentration in monoaromatics and the highest concentration of tetra-aromatics+; meanwhile CHOX had the highest concentration in monoaromatics and the lowest in high aromatic compounds (tetra-aromatics+). These findings can be explained taking into account that polyaromatics can readily react with molecular oxygen, leading to more polar (water-soluble) compounds. ,− …”

Current trends in nanotechnology for bioremediation

“…It enables remediation in deeper soils and is compatible with other technologies like bioremediation and is an expanding tool for contaminant cleanup (Huang et al, 2016). The development and use of nanofertiliser (bio stimulation and bioaugmentation), nanominerals (bio stimulation) or green synthesised nanooxidisers (PAH oxidation) could be explored to properly exploit the massive significance of nanoremediation in PAH removal (Nkansah et al, 2012;Jin et al, 2016;Lawal, 2017). Transgenic approaches and advances in protein and genetic engineering techniques have opened up new avenues for the development of genetically modified microorganisms (GMOs) and plants to function as 'exclusive biocatalysts' in which certain desirable enzymes or degradation pathways from the diverse organism are brought together in a single host with the aim to perform specific reactions.…”

“Broken-hearted” carbon bowl via electron shuttle reaction: energetics and electron coupling

“…31 Indeed, as presented in this report, release of strain energy can be the driving force for planarization of the naturally curved buckybowl surface (e.g., C 20 H 10 , corannulene), since there is no direct route to cleave a C]C bond, except through uncontrollable ash vacuum pyrolysis 22,27,29 or addition of a directing group (and a catalyst). 32 Although there are numerous reports of catalytic hydrocracking of planar polycyclic aromatic hydrocarbons (PAHs) i.e., increasing the ratio of hydrogen-to-carbon, [33][34][35][36] there are very few accounts on C-C bond cleavage following the hydrogenation step. 37 The literature precedent for C-C bond scission primarily relies on the assistance of transition metal catalysts, high hydrogen pressure, elevated temperatures, or a combination of all three parameters.…”